Presently, the electrical power system in a jet aircraft consists of a plurality of electrical power generation alternators which may be mechanically connected to the main compressor shaft of the jet engine or may be driven by an auxillary gas turbine engine. The larger jet aircraft, such as the Boeing 747, contain in addition to the main generators mechanically connected to the jet engines, auxiliary power generators which are driven by a separate gas turbine engine.
In these conventional type of power generation means, it is necessary to air cool the generators since under normal conditions the power output is considerable and the heat loss incident to mechanical generation means does require cooling.
Of necessity, the conventional electrical power generation means aboard a jet aircraft are bulky, heavy and occupy precious space. Obviously also there is the need for maintenance as the generators are mechanical systems rotating usually at high speeds, i.e., 6,000 RPM or greater, and do suffer the usual problems associated with rotating mechanical devices. In addition, the aforementioned generators consume engine power and fuel.
In missiles, the power generation system comprises so-called squib-activated batteries which comprise high energy, compact, and short life units. This is entirely compatible with the missile system as the active life span of a missile is a relatively short period of time. However, the battery power system aboard the missile does suffer shortcomings as its being a relatively heavy unit means that the rocket propulsion system must lift the batteries along with the missile, which requires precious fuel.